1 billion birds disappeared in N America since 1970

A
third of birds in North America threatened with extinction

State
of North America's Birds report finds ocean, tropical birds most
threatened

A
billion birds have disappeared from North America since 1970, and a
third of bird species across the continent are threatened with
extinction, a new report says.

The
first State
of North America's Birds report finds
that of 1,154 bird species that live in and migrate among Canada, the
U.S. and Mexico, 432 are of "high concern" due to low or
declining populations, shrinking ranges and threats such as
human-caused habitat loss, invasive predators and climate change.Steven
Price, president of Bird Studies Canada, a member of the North
American Bird Initiative behind the report, says that since
1970, "the estimate is we've lost at least a billion birds from
North America…. The trend lines are continuing down. They have to
be turned around or will fall below a threshold where they can be
recovered."

Ocean
birds like northern gannets are among the most threatened, a new
report suggests. Many that nest in Canada migrate to the Gulf of
Mexico and were hard hit by the 2010 oil spill.

Most
threatened, with more than half the species of "high concern"
are ocean birds such as northern gannets, tropical and sub-tropical
birds, including many that breed in Canada and the U.S., but winter
in Mexico.There
are also steep declines in coastal shorebirds like semipalmated and
western sandpipers and red knots, which have lost 90 per cent of
their population; grassland birds such as the greater sage grouse,
Sprague's pipit and chestnut-collared longspur; and aridland
birds.

Once
one of the most common forest birds in eastern North America, the
wood thrush has decreased by almost 70% in the last 40 years. Wood
thrushes and many warblers breed in Canada's forests, but winter in
tropical forests of Mexico that are threatened by logging. ((Isaac
Sanchez))

The
North American Bird Conservation Initiative is a collaboration of
conservation groups and scientists, in all three countries. The
report was released partly to mark the 100th anniversary of the
1916 Migratory Bird Convention between Canada and the U.S.
Information in the report is based on data collected by citizen
scientists through bird surveys and counts since the 1970s and
analyzed over the past 18 months.It
follows a similar
report that focused on Canada in 2012 and
found a 12 per cent drop in bird populations since 1970.But
because many birds make very long migrations, Canada's birds are "not
really Canada's — they're shared across three nations," said
Price.For
example, northern gannets nest in four colonies on Canada's East
Coast, but migrate to the Gulf of Mexico, where they "got hit
very hard by the Gulf oil spill" in 2010.

Waterfowl
such as wood ducks are making a big comeback due to wetland habitat
protection and hunting restrictions. (Sean Kilpatrick/The Canadian
Press)

Wood
thrushes and many warblers breed in Canada's forests, but winter in
tropical forests of Mexico that are being logged.Many
grassland birds rely on habitat that run from Canada's
Prairies down to Mexico's Chihuahuan grasslands — nearly 70 per
cent of birds that migrate between the northern and southern
grasslands have disappeared since 1970."It's
our North American Serengeti," Price said of the region. "We
have so many endangered birds or birds in decline because we have
really dissected and divided the grasslands and prairies."Some
birds also face domestic threats — many coastal birds on the Haida
Gwaii islands on Canada's West Coast are threatened by invasive
predators such as raccoons and rats. They include species like the
ancient murrelet, Cassin's and rhinoceros auklets, the fork-tailed
storm petrel and the black oystercatcher.The
report did have some good news. Populations of waterfowl such as wood
ducks and canvasbacks and birds of prey such as the osprey and
peregrine falcon continue to rebound. Wetland habitat protection,
hunting restrictions and bans of pesticides such as DDT have
helped bring them back.